Method and apparatus for improving delivery of an agent to a kidney

ABSTRACT

Methods for more uniformly delivering drugs or other treatment agents locally to the vasculature of a mammal are disclosed. These methods use one or more strategies to facilitate rapid mixing with the blood flowing past a device or otherwise improve the uniformity of drug delivery. Some of these strategies employ medical devices with diffusion members.

BACKGROUND

Many diseases that affect organs develop over a decade or more. During this time, the function of the organ diminishes. The end-stage of many of these diseases is a transplant or some other treatment to supply artificially the organ's function—dialysis in the case of kidney disease such as end-stage renal disease, for example. A number of factors including immune system disorders or diabetes can cause these types of diseases.

Different diseases call for different treatments depending upon the dysfunction of the organ. For many of these diseases, the standard for treatment, short of a transplant, is drug-based. Drug-based treatments are usually systemic and typically use a pill or infusion of a solution of the drug in a carrier. These delivery methods are systemic because the patient's whole system is treated. But systemic treatment requires supplying the whole system drugs at levels high enough to be effective at the target organ. Achieving effective levels at the target organ frequently requires delivering toxic levels throughout the remainder of the system.

On the other hand, locally delivering the drug can alleviate some of the problems with systemic treatment. For instance, local delivery side-steps supplying the drug system-wide allowing for effective local drug levels while maintaining much lower system-wide levels, levels that are frequently benign to the patient.

But local delivery presents its own set of challenges. Typically, with local delivery, the drug enters the bloodstream upstream of the desired treatment site. Another technique involves injecting the drug into a (temporarily) unperfused region of the vasculature near or in the diseased organ. This technique can use an occlusion device upstream of the delivery region to inhibit or stop blood flow. In either case, the natural laminar flow of blood does not always promote effective mixing between the drug and blood.

Ineffective mixing can prevent the drug from evenly reaching its target organ or region's cells. For example, delivery upstream of an arterial branch coupled with ineffective mixing can result in more drug being delivered down one branch than another.

What is needed is a delivery technique for local delivery that provides effective mixing between the blood and the drug. This need is especially acute for delivery to the kidney because the kidney contains a highly branched arterial vasculature.

SUMMARY

The present invention is directed towards a method of delivering drug or therapeutic agent containing solutions to an organ having branched vessels wherein the method uses at least one step that improves the uniformity of the delivery of the drug or therapeutic agent among the branched vessels.

The step can be any one or any combination of normalizing the viscosity of the therapeutic agent solution towards that of blood; delivering a delivery catheter with a delivery port that has a geometry that causes increased mixing between the blood and therapeutic agent solution; delivering a delivery catheter with at least one delivery port wherein the delivery fosters increased turbulence around the delivery port; decreasing the infusion rate of the therapeutic agent solution; or increasing the number of delivery ports.

In some embodiments of the present invention, a step that improves the uniformity of the delivery of the drug or therapeutic agent among the branched vessels is a step that causes the range of therapeutic agent concentrations delivered to the vessels to be small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds the minimum therapeutic dose, while the total drug delivery to the vessel that receives the highest concentration is 50-200; 75-175; or 90-150 percent of the maximum therapeutic dose.

In some embodiments of the present invention, a step that improves the uniformity of the delivery of the drug or therapeutic agent among the branched vessels is a step that causes the range of therapeutic agent concentrations delivered to the vessels to be small enough so that the total drug delivery to the vessel that receives the highest concentration falls within the maximum therapeutic dose, while the total drug delivery to the vessel that receives the lowest concentration is 100-300; 150-250; 175-225 percent of the minimum therapeutic dose.

In some embodiments of the present invention, a step that improves the uniformity of the delivery of the drug or therapeutic agent among the branched vessels is a step that causes the range of therapeutic agent concentrations delivered to the vessels to be small enough so that the average amount of drug delivered to each vessel falls within a range defined as a 85, 90, 95, 98, or 99 percent confidence interval calculated from the standard deviation of the average amount of drug delivered for the vessel with the highest such standard deviation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a flow chart of a method for delivering a treatment agent to an organ or region.

FIG. 2 shows a cross-sectional side view of a kidney and a device for delivering a treatment agent to the kidney.

FIG. 3 is a schematic view of a catheter and an expandable diffusion member.

FIG. 4 is a schematic side and end view of an umbrella-like embodiment of a therapeutic agent delivery device.

FIG. 5 is a schematic side view of a therapeutic agent delivery device of FIG. 4 situated in the delivery catheter.

FIG. 6 is a schematic side view of the therapeutic agent delivery device of FIG. 5 situated within the vessel lumen of a mammal.

FIG. 7 is a schematic side view of the therapeutic agent delivery device of an embodiment of the invention that has serpentine struts.

FIG. 8 is a side view and end schematic view of an embodiment of a therapeutic agent delivery device showing retracted coils.

FIG. 9 shows an expanded-coil-view of the therapeutic agent delivery device of FIG. 8.

FIG. 10 illustrates a representation of uniform blood flow through a vessel lumen and around the therapeutic agent delivery device of FIG. 8.

FIG. 11 illustrates a representation of locally turbulent blood flow around the expanded-coil-arrangement of the therapeutic agent delivery device of FIG. 8.

FIG. 12 is a graph showing absorbance versus vessel number for experiments in which the catheter injection position was placed at the proximal position and held constant and the infusion rate was varied.

FIG. 13 is a graph showing absorbance versus vessel number for experiments in which the catheter injection position was placed at the middle position and held constant and the infusion rate was varied.

FIG. 14 is a ground showing absorbance versus vessel number for experiments in which the catheter injection position was placed at the distal position and held constant and the infusion rate was varied.

FIG. 15 is a graph showing standard deviation of the absorbance values for 6 vessels versus catheter injection position for a Veripath catheter.

FIG. 16 is a graph showing absorbance versus vessel number for experiments in which the infusion rate was held constant at 1 mL per minute and the catheter injection position was varied.

FIG. 17 is a graph showing absorbance versus vessel number for experiments in which the infusion rate was held constant at 5 mL per minute and the catheter injection position was varied.

FIG. 18 is a graph showing absorbance versus vessel number for experiments in which the infusion rate was held constant at 15 mL per minute and the catheter injection position was varied.

FIG. 19 shows the coefficient of variance (COV) for a variety of catheter designs as described in Example 15.

DETAILED DESCRIPTION

The following description of several embodiments describes non-limiting examples that further illustrate the invention. All titles of sections contained herein, including those appearing above, are not to be construed as limitations on the invention, but rather they are provided to structure the illustrative description of the invention that is provided by the specification.

Unless defined otherwise, all technical and scientific terms used in this document have the same meanings as commonly understood by one skilled in the art to which the disclosed invention pertains. The singular forms a, an, and the include plural referents unless the context clearly indicates otherwise. Thus, for example, reference to “fluid” refers to one or more fluids, such as two or more fluids, three or more fluids, etc.

The features, aspects, and advantages of the invention will become more apparent from the following detailed description, appended claims, and accompanying drawings.

For purposes of this document, the portion of a delivery device designed to create turbulence in the blood flow is sometimes called a diffusion member or an expandable diffusion member.

FIG. 1 shows a flow chart of a method for delivering a treatment agent to a kidney. In one such embodiment, the method includes introducing a delivery device to a point within a renal artery or a renal segmental artery that supplies the renal cortex (block 102). Alternatively, the point may be within the renal cortex. The delivery device broadly includes any medical device for insertion into a physiological lumen to permit injection or withdrawal of fluids of varying viscosities, to maintain patency of a blood vessel lumen or an area defining the lumen, or for other purposes. The delivery device may further include any medical device capable of releasing a treatment agent after insertion into a physiological lumen. The point the delivery device is introduced at may be a treatment site or a region adjacent to a treatment site. The treatment site may be a diseased region within a renal vessel or other tissue of a kidney or other organ.

In one embodiment, the treatment agent is delivered according to conditions that create turbulent blood flow within a vessel region where the treatment agent is delivered (block 104). The term “turbulent blood flow” as used herein generally refers to a flow profile characterized by a chaotic or agitated blood flow or flow profile otherwise modified from a normal or steady state flow. Modified flow profiles may include rapid variations of pressure, flow direction or velocity. For example, in some embodiments, turbulent blood flow arises from partially occluding the vessel lumen by about 60% to about 90%.

Typically, the flow profile of blood flowing through the renal artery to the kidney is laminar, meaning the fluid flows in parallel layers, or streams, with little or no disruption between the layers. This profile continues along the kidney opening, or Ilium, and into the segmental arteries leading to the glomerular capillaries within the renal cortex. Thus, when the delivery device releases the treatment agent from a single point into one of these streams of a healthy kidney, most of the treatment agent is carried only to the kidney region at the end of the stream. In this respect, only a small portion of the kidney receives the treatment agent.

Moreover, the disease may reduce or stop altogether blood flow to those diseased regions especially in need of the treatment agent. In such cases, even when the treatment releases the treatment agent into a path normally destined for the diseased region, it may not reach that region. Treatment may overcome such problems by creating turbulence within the flow profile followed by treatment agent delivery into the turbulent blood flow. In particular, the turbulent conditions will facilitate mixing of the treatment agent with the blood and disrupt the streams typically found within the kidney causing more even distribution of the treatment agent throughout the kidney.

Liquid Flowing Streams

When blood or similar fluids experience flow parameters similar to those seen in a blood vessel, these fluids flow through a vessel lumen in substantially laminar flow—there is little mixing from point to point within the stream. If one looks at a cross-section of the lumen, the mixing between areas in one quadrant or stream and another quadrant or stream is very low. This means that introduction of a therapeutic-agent solution at a single point can result in a heterogeneous mix between the blood and solution. For instance, solution introduction at a lower rate will not substantially disturb the laminar flow behavior of the blood as it moves through the vessel lumen. Thus, downstream of the injection site, the blood is heterogeneous: some sectors contain blood mixed with more therapeutic-agent solution while others contain blood mixed with substantially less therapeutic-agent solution. Of course, one of ordinary skill in the art would expect that over time (distance traveled from the injection site), the blood from these various sectors would eventually mix yielding a substantially homogeneous blood-therapeutic-agent mixture.

This lack of mixing is inconsequential for systemic delivery. Systemic delivery of the injected therapeutic-agent solution provides longer times for the solution and blood to mix. But mixing must occur more quickly for local delivery. Local delivery methodologies frequently employ therapeutic-agent delivery within centimeters of the drug's target region. At typical blood flow rates, this short distance may yield mixing times of a few seconds or less.

If the goal is to uniformly treat a region, the blood and therapeutic-agent solution should mix before the treatment region receives the blood—therapeutic-agent mixture.

Blood from one quadrant or another will travel along one path or another in regions of high tortuosity. If the blood in one quadrant has not mixed with the therapeutic-agent solution, then pathways in the high tortuosity region that are fed by that blood quadrant will not see the same therapeutic-agent concentration as pathways that are fed from other sectors. This difference in therapeutic-agent concentration unavoidably leads to differences in treatment for tissues located along one pathway and those located along another pathway.

So, regional treatment may be better served by locating therapeutic-agent solution delivery points well ahead of the targeted region. But this is only a successful strategy if there is a sufficient vessel length ahead of the treatment region.

For instance, one may desire a longer vessel length within which to accomplish mixing between a therapeutic-agent solution and the blood. But another goal of regional delivery is for the therapeutic agent to substantially remain or arrive at the treatment region without substantial delivery to ancillary regions. There are instances when delivering far enough upstream of the target region to achieve adequate mixing of the therapeutic-agent solution and the blood would likewise require delivering the therapeutic-agent solution upstream of a vessel branch that would allow some of the therapeutic agent to follow the unintended branch rather than the intended one.

This circumstance, among others, leads to other strategies for promoting uniform regional drug delivery.

One class of strategies employs a turbulence-inducing element near the point at which the therapeutic-agent solution enters the vessel. In principle, having a turbulence-inducing member causes the non-mixing sectors discussed above in the laminar-blood-flow portion to mix. This mixing promotes adequate homogenization along a shorter path than if no turbulence-inducing elements were present.

Turbulence-inducing elements come in a variety of forms. Typically, the turbulence-inducing element functions by partially occluding the vessel or by forcing the blood to change directions as it flows by the element.

Another strategy for improving uniform regional drug delivery is to prepare the therapeutic-agent solution so that its viscosity more closely matches that of the blood, e.g. around 3-4 centipoise. Fluids flowing together through a vessel that have mismatched viscosities remain segregated for a longer time as they move through the vessel. The closer the viscosity match between the blood and therapeutic-agent solution, the easier or quicker the two mix.

Yet another strategy is to supply the therapeutic-agent solution at multiple positions near the distal end of a drug delivery device or catheter. This is believed to have at least two important effects: multiple injection positions promote turbulence in the blood flowing past the delivery device and multiple injection positions cause the therapeutic-agent solution to enter more individual streams or sectors within the blood flow.

Decreasing the speed of delivering the therapeutic-agent solution promotes more uniform therapeutic-agent delivery. Also, the geometry of the delivery port can be selected to encourage mixing. Such geometries can include structures with delivery ports that occupy a larger cross sectional area of the vessel, which allows for greater coverage of the fluid flow and improves mixing.

In one aspect, conditions creating turbulent blood flow may include partially occluding a region of the lumen so as to provide a constricted pathway for blood flow (e.g., about 60% to about 90% lumen occlusion). The narrowed pathway causes the speed of the blood flowing through that region to increase resulting in turbulent blood flow. The treatment agent may then be injected into that region. In other embodiments, the conditions creating a turbulent blood flow may include injecting a treatment agent within a vessel lumen in a direction perpendicular to the direction of blood flow. In this aspect, the stream of treatment agent alters the normal direction of blood flow, disturbing the normal flow path, and causing turbulence. This turbulence mixes the treatment agent with the blood for delivery to the treatment site. In addition, this turbulence may disrupt the downstream laminar flow profiles within the kidney. The homogenous distribution of the treatment agent throughout the blood flowing to the kidney and disruption of flow profiles within the kidney facilitates a substantially uniform distribution of the treatment agent solution throughout the kidney tissues or the tissues of other organs.

Representatively, a femoral artery may be punctured and delivery device 224 may be advanced through the femoral artery, to aorta 200, and then into renal artery 202. Alternatively, one may advance the delivery device 224 through a brachial artery, down aorta 200, and into renal artery 202. In still further embodiments, an external iliac artery may be punctured and delivery device 224 may be advanced through the external iliac artery to a common iliac artery, to aorta 200, and then into renal artery 202.

It is further contemplated that delivery device 224 may be introduced to a point within kidney 204 using retroperitoneal insertion. In this aspect, a distal end of delivery device 224 may be inserted through the back of the patient adjacent to the kidney 204. Delivery device 224 may then be advanced through a surface of kidney 204 to a point within renal cortex 218 adjacent to glomerulus 216. In this aspect, when the treatment agent is delivered with delivery device 224, it localizes within an area proximal to glomerular capillaries within the kidney. Alternatively, delivery device 224 may be introduced through a back region of the patient and into renal artery 202. In this embodiment, the treatment agent may then be delivered by delivery device 224 through renal artery 202 to a desired treatment site.

In an embodiment illustrated in FIG. 2, a treatment agent loaded within delivery device 224 may be released into, for example, renal artery 202 such that the treatment agent flows through segmental artery 208 and into glomerulus 216. In one embodiment, the treatment agent may be loaded into a carrier (such as a particle) having a large enough diameter such that the carrier lodges within a narrow lumen of a capillary within the glomerulus 216. The-FIG. 2-exploded-view of glomerulus 216 shows this aspect. In this embodiment, treatment agent 220 flows into glomerulus 216 and lodges within the lumen. For example, in some embodiments the treatment agent may have a diameter from about 8 microns to about 15 microns. Thus, release of the treatment agent from within the carrier localizes it at glomerulus 216, and the treatment agent remains at a specific treatment site within the kidney.

Useful treatment agents will be discussed below after discussing several embodiments of delivery devices according to embodiments of the invention.

Referring to FIG. 3, the device 310 sits within the lumen of vessel 320 before delivering the drug. As shown in FIG. 3, the device 310 has a catheter portion 330 connected to an expandable diffusion member 340. The catheter portion 330 contains a diffusion member delivery lumen 350 and a drug delivery lumen 360. In the figure, the drug delivery lumen 360 is shown coaxial with the diffusion member delivery lumen 350. But this need not be the case for any embodiments described in this document. For each of the embodiments in this document described as having a diffusion member delivery lumen 350 coaxial with the drug delivery lumen 360, a corresponding embodiment exists in which these lumens are not coaxial.

In operation, the device 310 is placed into a desired vessel 320 upstream of the desired treatment region or organ. The expandable diffusion member 340 is deployed creating a region of increased turbulence in the blood flow near the expandable diffusion member 340. Upstream of the expandable diffusion member 340 within the region of increased blood turbulence or upstream of that region, the therapeutic agent can be released from drug delivery lumen 360.

When the drug reaches the turbulent region, it mixes more thoroughly with the blood than it would have if the expandable diffusion member 340 were not present. Past the turbulent region, the blood and drug mixture returns to laminar flow 370. In some embodiments, the expandable diffusion member 340 creates a turbulent region that ranges from upstream of the diffusion member 340 to downstream of the member. After drug delivery, the expandable diffusion member 340 is retrieved.

FIG. 4 shows an embodiment of the therapeutic agent delivery device 2010 of the invention. It comprises, at the distal end, a floppy, guide-wire-like tip 2020. Further back from the guide-wire-like tip 2020 and coaxial to the delivery device's 2010 main wire 2030 sits a self-expanding structure 2090. The self-expanding structure 2090 and struts 2060 connect to a shaft (not shown) by a ring (not shown). In some embodiments, the struts 2060 are constructed from the same material as the ring. In some embodiments, the struts 2060 are integral to the ring.

Further back from the self-expanding structure 2090 and also coaxial to the main wire 2030 is a mounting ring 2040 that attaches ring to the main wire 2030.

As depicted in FIG. 5, the main wire 2030 is situated within an outer sheath 2070. Between the main wire 2030 and outer sheath 2070 is a passageway 2080 with which to infuse drug solutions or other therapeutic agents. The blood flow around the self-expanding structure 2090 is indicated as 2100.

In some embodiments, the self-expanding structure 2090 is composed of struts 2060 and a flexible membrane 2050. In these or other embodiments, the flexible membrane 2050 is composed of polyurethane, nylon, or pebax. It can take a number of different forms. In some embodiments, the flexible membrane 2050 becomes taut when deployed; in other embodiments, the flexible membrane 2050 remains at least somewhat slack when deployed. Similarly, the attachment of flexible membrane 2050 to the strut 2060 can also take a number of different forms. In some embodiments, the flexible membrane 2050 is attached or bonded to strut 2060 within the entire contact region between the flexible membrane 2050 and the strut 2060. In other embodiments, the flexible membrane 2050 is attached or bonded to strut 2060 at the distal end of strut 2060. The struts 2060 are composed of a flexible or elastic material such as nitinol, a polymer, or polymer-coated stainless steel.

In some embodiments, such as shown in FIG. 6, the floppy, guide-wire-like tip 2020 also contains a distal infusion port 2110. Some embodiments have both a passageway 2080 and a distal infusion port 2110 for supplying a drug or other therapeutic agent.

In some embodiments, the struts 2060 are serpentine such as shown in FIG. 7—serpentine struts 2111.

In operation, the therapeutic agent delivery device 2010, as shown in FIG. 4, is inserted into the patient percutaneously and then threaded through the patient's vasculature until the device resides near or upstream of the desired treatment region. Threading the device 2010 through the tortuous vasculature uses a guide-wire-like tip 2020 to pass through or to cross the curves of the vasculature. Once positioned, delivery of the therapeutic agent requires the deployment of the self-expanding structure 2090. Typically, deployment employs retraction or other manipulation of the outer sheath 2070, which has been constraining the self-expanding structure 2090, such that the manipulation frees the self-expanding structure 2090.

Without wishing to be bound by any particular theory, the deployed self-expanding structure 2090 is believed to disturb the local blood flow causing a turbulent region near the therapeutic agent delivery device 2010.

After the deployment of the self-expanding structure 2090, drugs or other therapeutic agents are delivered through the passageway 2080. This constitutes delivery of the therapeutic agent or drug upstream of the turbulent blood region. In an alternative embodiment, such as shown in FIG. 6, drugs or therapeutic agents are delivered from a drug delivery port located distal to the self-expanding number 2090. This results in drug delivery downstream of the turbulent blood region.

Another embodiment of the invention is also directed at a device adapted for percutaneous delivery into the vasculature of a mammal and adapted to expand the expandable diffusion member within the vessel of the mammal. This class of embodiments includes an infusion catheter for delivering drugs or other therapeutic agents to the mammal's vasculature. In some embodiments, the therapeutic agents are diabetic nephropathy treatment agents. In FIG. 8, the device 3000 includes at least one, standard, single-lumen infusion port 3001 located at or near the distal end of an infusion catheter 3002.

Coils 3030 connect to the outside of the infusion catheter's walls 3020 near the distal end of the infusion catheter 3002. The coils 3030 have a substantially rectangular shape and are cut from nitinol foil or sheets, but those of ordinary skill in the art will recognize that the cross-section of these coils 3030 can take just about any shape. The coils 3030 are shown collapsed in FIG. 8 and deployed in FIG. 9. In addition to nitinol, the coils 3030 can be formed of any material capable of springing open or self-expanding from a retracted position to an expanded or deployed position.

The device 3000 also comprises a sheath 3010 that is movably affixed to the distal end of the device 3000, but is manipulable from a control handle (not shown) connected to the proximal end of the device 3000. When in the closed position, the sheath 3010 maintains the coils 3030 in a collapsed configuration. When in the open position, the sheath 3010 no longer interferes with the coils 3030, and they assume the shape shown in FIG. 9 in their deployed position. In addition to providing a turbulence-inducing member, the coils 3030 also serve to center the catheter within the vessel lumen. The coils 3030 allow for adjustments for varied turbulence inducing effect or for varied radial force, as desired. (Varying the radial force varies the force with which each coil 3030 presses against the artery or vein.)

FIG. 10 depicts the device 3000 in cross-section situated around guide wire 3060 and within vessel 3050 with coils 3030 in their retracted position. The arrows identified as 3079 indicate the blood flow within the vessel 3050 and the uniformity of the arrows represents substantially laminar flow.

FIG. 11 depicts the device 3000 in cross-section situated around guide wire 3060 and within vessel 3050 with coils 3031 in their deployed position. The arrows identified as 3081 indicate the blood flow within the vessel 3050 and the chaos of the arrows represents turbulent flow. The outer sheath 3080 is shown in its retracted position. Drug particles 3070 are shown emerging from the device 3000 into the turbulent flow, which causes mixing between the drug particles 3070 and the blood.

As can be seen in FIG. 12-FIG. 15, the degree that the amount and distribution of dye as measured by its absorbance changes from one vessel to the next as the injection rate changes and depends upon the distance between the arterial branches and the injection position. Further distances, for example, proximal (FIG. 12) and middle (FIG. 13) show less dependence on injection rate than shorter distances such as distal (FIG. 14).

Without wishing to be bound by any theory, the data supports the observation that injection rate does correlate with absorbance uniformity. In FIG. 14, the higher injection rate shows less uniform absorbances among the vessels than the lower injection rates when the catheter is positioned distally.

Despite this correlation for distally injected drugs solutions, the absorbances for the middle and proximal injection positions do not correlate with injection rate. This difference seems to indicate that injection position more strongly affects absorbance uniformity than does injection rate. Perhaps the higher injection rates yield less uniform mixing of the blood initially, but having a longer mixing time or distance overcomes this initially poor mixing.

FIG. 16-FIG. 18 shows the difference in absorbance for each of six vessels in a kidney model while maintaining the injection rate (and catheter design). As discussed above for FIG. 12-FIG. 15, the data appears to show that injection rate matters to absorbance uniformity but less so than does catheter position.

FIG. 19 shows the coefficient of variance (COV) for a variety of catheter designs as described in Example 15.

The experimental section contains a description of these catheter designs. Each design was used three times for each regimen. The COV is a measure of the variance of the standard deviations of the six vessels in a kidney model. Thus, smaller values indicate smaller standard deviations of absorbance among the vessels. And therefore, they indicate higher uniformity in drug distribution among the vessel and ultimately better mixing upstream of the vessel branches.

For most of the catheter designs, the data shows similar COVs for each of the separate runs, which indicates that the experiments yield reproducible results.

The date illustrates the catheter design matters to drug mixing. Generally, the design induces less turbulence than the SCLS design followed by BOIC-2-atm and BOIC-4-atm. Therefore, apparently increasing turbulence around the injection position increases mixing between the blood and the drug solution.

Treatment Agents

As used herein, treatment agents are intended to include, but are not limited to, drugs, biologically active agents, chemically active agents, therapeutic agents, and the like, and pharmaceutical compositions thereof, which can be used to deliver a treatment agent to a treatment site within a kidney as described herein. Treatments agents may contain a mixture of active agents.

In one embodiment, the treatment agent may include a property to inhibit a biological process contributing to nephropathy. Such biological processes may include, but are not limited to, changes in glomerular basement membrane, changes in mesangial matrix deposition and podocyte attachment or apoptosis.

In one embodiment, the treatment agent may include a drug. The drug may have a property to inhibit undesirable effects of the renin-angiotensin system in the kidneys. The renin-angiotensin system responds to a decrease in the perfusion of the juxtaglomerular apparatus found in afferent arterioles of the glomerulus of the kidney by constricting glomerular arterioles. Such constriction causes blood to build up in the glomerulus and increase glomerular pressure. Representative drugs that may act to inhibit this process include, but are not limited to, angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and renin inhibitors.

In still further embodiments, the treatment agent may include a drug to inhibit protein kinase C. Representative drugs may include, but are not limited to, rubox-istaurin (LY333531), enzastaurin (LY317615), bisindolylmaleimide IX, chelerythrine, edelfosine, edelfosina, ET180CH3, H-7, HA-100, H89, HA-1004, Ro 31-8220, rottlerin, staurosporine and quercetin.

The transforming-growth-factor-beta system contributes to the progression of renal damage due to stimulation of extracellular matrix deposition. Thus, in some embodiments, the treatment agent may include an agent having a property to inhibit transforming growth factor beta, its receptor and SMAD and other signaling molecules downstream of the receptor. Representative inhibitors may include, but are not limited to antisense molecules, ribozymes, siRNA, antibodies, receptor kinase inhibitors and other small molecule inhibitors such as halofuginone, sirolimus, everolimus, biolimus ABT578 and nuclear receptor agonists such as estradiol, retinoids, and peroxisome proliferator-activated receptors (PPAR) agonists.

It is further recognized that connective tissue growth factor (CTGF) is present in glomeruli in patients with diabetic nephropathy. CTGF is a member of the centrosomin (CCN) family of proteins, which regulate biological processes including stimulation of cell proliferation, migration, and adhesion. Probably, expression of CTGF in diabetic kidneys contributes to the development of glomerulosclerosis by affecting matrix synthesis and its turnover. In this aspect, the treatment agent may include an agent having a property to inhibit connective tissue growth factor. Representative agents having a property to inhibit connective tissue growth factor may include, but are not limited to antibodies, interleukin-1 (IL-1) alpha and beta, Rho A GTPase inhibitors, and p38 MAP kinase inhibitors.

In some embodiments, the treatment agent may be modified to enhance its uptake into the desired tissue. In this aspect, the treatment agent may be delivered to the desired tissue in a formulation that may include vasoactive agents as enhancers of vascular permeability called excipients, such as thrombin, bradykinin and histamine. These excipients have properties that increase endothelial porosity and thereby enhance uptake of the treatment agent into the tissue.

The treatment agent may be delivered in a form including, but not limited to, a solution. For example, in some embodiments, a desired amount of treatment agent is mixed with saline or an iodine-free contrast media to form the solution.

In some embodiments, the treatment agent may be delivered to the desired tissue in a carrier. In one aspect, the carrier may be a sustained-release carrier that allows for controlled release of the treatment agent over time at the desired treatment site. “Carrier” includes a matrix that contains one or more treatment agents. A suitable carrier may take the form of a nanoparticle (e.g., nanosphere), microparticle (e.g., microsphere) or liposome as the situation may dictate. The carrier with encapsulated treatment agent may be incorporated into a solution including an oily material for delivery to the desired tissue.

The carrier may be a bioerodable carrier (hereinafter interchangeably referred to as sustained-release carriers) infused with a treatment agent. Suitable materials for sustained-release carriers include, but are not limited to, encapsulation polymers such as poly (L-lactide), poly (D,L-lactide), poly (glycolide), poly (lactide-co-glycolide), polycaprolactone, polyanhydride, polydioxanone, polyorthoester, polyamino acids, or poly (trimethylene carbonate), and combinations of these materials.

Treatment agents, including treatment agents combined with a carrier (e.g., a sustained release carrier), having a size greater than about 10 microns can become trapped in the glomerular capillaries when introduced into the renal artery. In this aspect, the treatment agent may be released over time at a point within the glomerular capillaries. In other embodiments, the carrier size may be between about 1 micron to 100 microns, still further between about 8 microns to about 15 microns and in some embodiments between about 1 micron to 2 microns. In other embodiments, the carrier size may be between about 10 microns and 14 microns. In still further embodiments where the treatment agent is delivered at a point outside of a vessel lumen, such as the kidney cortex, the treatment agent or a carrier encapsulating the treatment agent may be any size capable of being delivered through a lumen of the delivery device, such as for example, a size as small as one nanometer to as large as about 100 microns.

Various methods may be employed to formulate and infuse the carrier with one or more treatment agents. The embodiments of the composition of infused carrier may be prepared by conventional methods where all components are combined then blended. In some embodiments, carriers may be prepared using a predetermined amount of a polymer or a pre-polymer that is added to a predetermined amount of a solvent or a combination of solvents. The solvent is mutually compatible with the polymer and is capable of dissolving the polymer into solution at the desired concentration. Examples of solvents may include, but are not limited to, dimethylsulfoxide (DMSO), Dimethyl Acetamide (DMAC), chloroform, acetone, water (buffered saline), xylene, acetone, methanol, ethanol, 1-propanol, tetrahydrofuran, 1-butanone, dimethylformamide, dimethylacetamide, cyclohexanone, ethyl acetate, methylethylketone, propylene glycol monomethylether, isopropanol, N-methyl pyrrolidinone, toluene and mixtures of these materials.

By way of example, and not limitation, the polymer may comprise from about 0.1% to about 35%, more narrowly about 2% to about 20% by weight of the total weight of the total solution, and the solvent may comprise from about 65% to about 99.9%, more narrowly about 80% to about 98% by weight, of the total weight of the total solution. Specific weight ratios depend on factors such as the material from which the delivery device is made and the geometrical structure of the device.

Sufficient amounts of treatment agent are dispersed or dissolved in the carrier. The amount of treatment agent introduced into the carrier may be any amount sufficient to inhibit a biological process, such as a biological process contributing to nephropathy, when released within the renal system. The treatment agent may be dissolved or suspended. If the treatment agent is not completely soluble in the composition, operations including mixing, stirring, or agitation may be employed to effect homogeneity. The treatment agent may be added so that the dispersion is in fine particles. The mixing of the treatment agent may be conducted in an anhydrous atmosphere, at ambient pressure and at room temperature.

In some embodiments using microparticles or nanoparticles, the microparticles or nanoparticles may be sustained release carriers prepared by a water/oil/water (WOW) double emulsion method. The WO phase, an aqueous phase containing treatment agent, is dispersed into the oil phase containing polymer dissolved in organic solvent (e.g., dichloromethane) using a high-speed homogenizer. Examples of sustained-release polymers that may be used include, but are not limited to, poly(D,L-lactide-co-glycolide) (PLGA), poly(D,L-lactide) (PLA) or PLA-PEEP co-polymers, poly-ester-amide co-polymers (PEA) and polyphophazines. The primary water-in-oil (WO) emulsion is then dispersed to an aqueous solution containing a polymeric surfactant, e.g., poly(vinyl alcohol) (PVA), and further homogenized to produce a WOW emulsion. After stirring for several hours, the microparticles or nanoparticles are collected by filtration.

In some embodiments, the sustained-release carrier is a liposome. “Liposomes” are approximately spherical artificial vesicles and can be produced from natural phospholipids and cholesterol. In one method, phospholipids are mixed with cholesterol in chloroform. Suitable phospholipids include, but are not limited to, dimyristoyl phosphatidyl choline or dipalmitoyl phosphatidyl ethanolamine. In some embodiments, a hydrophobic treatment agent may be added with an optional co-solvent. After mixing, the solvent (and optional co-solvent) may be evaporated with heat or ambient temperature in a round bottom flask. Resultant lipids may be deposited on the glass surface. In some embodiments, a hydrophilic treatment agent and water may be added to the flask and sonicated to form liposomes. The resultant solution may be pressure filtered through ceramic pore size controlled filters to reduce liposome particle size. In still further embodiments, the carrier is a microbubble formed by any technique deemed desirable.

In some embodiments, a surface of the carrier may be modified to enhance affinity of the encapsulated treatment agent to tissue lining the walls of the glomerular capillaries. In this aspect, the surface may be coated with binding agents. The binding agent may include a protein or small molecule that will facilitate retention of the carrier and encapsulated treatment agent at the treatment site to induce or modulate a therapeutic response through interaction with a specific binding site (e.g., a receptor within a cell or on a cell surface). Representative binding agents and their associated receptors include, but are not limited to, CD1 lb/CD1 8 (MAC-1) or aL/beta2 integrin (LFA-1) and intracellular adhesion molecule-1 (ICAM-1) receptor, integrin avb3 which binds to RGD-containing peptide and E-selectin which binds to Sialyl-Lewis glycoprotein.

A surface charge of the carrier may further be modified (e.g. positively, negatively or neutral) to accommodate and enhance binding characteristics to the glomerular tissue. The endothelial cells and basement membrane along the normal glomerular capillary walls are typically electronegatively charged. As diseases such as glomerulosclerosis and diabetic nephropathy progress, however, these cells slowly lose the electronegative charge. It is believed that modifying the carriers to have an electropositive charge will enhance binding of the carrier and encapsulated agent to the cells or membrane.

In this aspect, a carrier encapsulating the treatment agent may be modified by any standard method suitable for providing the carrier surface with an electropositive charge. In one embodiment, positively charged carriers may be synthesized by coating carriers with Chitosan. Alternatively, positively charged carriers may be made, for example, entirely of Chitosan in a water-in-oil emulsion process and crosslinked with glutaraldehye or genipin. In this aspect, the treatment agent may be swell-loaded in the crosslinked spheres. Still further, if the treatment agent is soluble at pH 5, the treatment agent may be incorporated into the initial Chitosan solution, if it does not subsequently react with the aldehyde crosslinker. Another approach for forming cationic carriers may include using a poly-lysine graft of PLGA.

In still further embodiments, a surface of the carrier may be coated with active agents or other species to enhance the range of functionalities of the product. For example, the surface may be coated with a monoclonal antibody that selectively binds to proteins expressed within the glomerulus (glomerular endothelium, basement membrane, podocytes) and tubules (tubular epithelium and basement membrane). A representative example is the monoclonal antibody anti CD90/Thy 1 that binds to OX-7 a glomerular basement membrane protein. Other useful proteins include nephrin and podocin.

EXPERIMENTAL

The data set out below were collected on a kidney model. This model allows the investigation of the degree of mixing between the blood and the administered therapeutic-agent solution. For accurate data collection, the model has several components: a model of the kidney vasculature; a fluidics system; an infusion system; a sample collection system, and ancillary data analysis systems or methods.

The vascular model contains an anatomically correct, 1:1 scale model of the renal arteries of a human kidney. This model is constructed from silicone. The vascular anatomy model was constructed in two different versions: one with a tortuous anatomy and one with a straight anatomy. The tortuous anatomy features a curved renal artery section between the model aorta and the arterial branches within the model kidney. And the straight anatomy features a straight and slightly shorter section in place of the curve renal artery section of the tortuous version.

At the ends of the six main kidney vessels, the anatomical model transitions back to standard tubing. Each tube is segregated so that solution can be collected individually so that the concentration of the therapeutic agent can be determined for each of the arteries in the model separately.

The fluidics system provides the fluid input to the model and sends the fluid output from the model arteries to the sample collection portion. To provide a realistic model of mixing in the kidney vasculature, the fluid flow through the model arteries should simulate the fluid flow through a real kidney. Fluid flow through this model kidney is marked by a flow rate and a pulsating pressure (just as in a real kidney, which exhibits a systolic and diastolic blood pressure).

For the data collected below, the flow rate was set to 600 mL per minute and the blood pressure was set at approximately 120 over 80 mmHg.

A standard roller pump provided the baseline flow rate. The pulsing pressure came from a pulsing pump. The pressures and flow rates are measured and controlled with pressure sensors.

Carrier Fluid for this data collection is either water or a water solution with 36% glycerol (which has a viscosity of around four centipoise). See Example 1.

For supplying the model drug solution, the model used an automated infusion pump. The pump for the infusion system was a Harvard syringe pump. For a typical experiment, the volume of model drug solution was one milliliter typically delivered at a rate of 5 mL per minute. The model drug solution for these data was a 35% solution of red food coloring in water. Thus, the model drug is red food coloring.

As discussed above, each model artery discharges into a dedicated collection vessel. Once collected, the concentration of drug (red dye) is measured using absorbance spectroscopy (Spectramax unit). The closer the concentrations of dye in the samples from each model artery are to each other, the more uniform the drug delivery down each artery. Thus, lower standard deviations of the concentrations from each of the individual model arteries indicate better mixing.

To represent homogeneity of mixing between the six independent vessels, the coefficient of variation (COV) is calculated. The COV is the ratio of the standard deviation to the mean. It can be used to compare the amount of variance between populations with different means. The absolute value of the coefficient of variation is referred to as the relative standard deviation (RSD) and is measure of precision among a set of data points. As it pertains to this invention, the COV or RSD is a measure of the variance of the standard deviations of the six vessels in a kidney model. A smaller COV or RSD value indicates smaller standard deviations of absorbance among the six vessels and thus, indicates higher uniformity in drug distribution among the vessel and ultimately better mixing.

These examples use a variety of delivery catheters:

A “Veripath catheter” is a Veripath brand catheter, which is a delivery catheter with a tapered tip and a single delivery port located at the distal end of the catheter;

A “VSH” is a Veripath brand catheter modified with side holes, which is a delivery catheter with a tapered tip and a delivery port located at the distal end of the catheter. The catheter has 15 additional holes placed near the distal end of the catheter but emerging from the sides of the catheter rather than the tip. Each of the holes is approximately 250 μm in diameter;

An “SCLS” is a Support Catheter Lifestream brand catheter. This catheter has 8 holes of around 300 micrometers diameter that are formed in the side of the catheter tip and spaced back from the tip of the catheter, which also has a single delivery located at the distal end of the catheter body;

An “SCE” is a Support Catheter Esprit brand catheter. This catheter has 9 holes of around 320 micrometers diameter that are formed in the side of the catheter tip and spaced back from the tip of the catheter, which also has a single delivery located at the distal end of the catheter body;

An “SC” is an Abbott Support Catheter, which is a single lumen catheter used for assisting guide wire delivery or infusing therapeutic agents;

An “AN” is an Accunet brand embolic protection device;

An “SB” is a spiral balloon infusion catheter with an independent infusion lumen.

A “PSB” is a Porous Spiral Balloon with a holes in a proximal taper;

A “BOIC2” is a balloon occlusion infusion catheter inflated to 2.0 atmospheres of pressure;

A “BOIC4” is a balloon occlusion infusion catheter inflated to 4.0 atmospheres of pressure;

Example 1

The circulating fluid in this example was a blood substitute (mixture of water and glycerol) with a viscosity of roughly 4 centipoise. An infusion catheter was tracked to the entry of the renal artery proximal to the branching of the main renal artery into the six smaller diameter branches. Each of the six branches emptied into separate vials. The model drug fluid contained red dye so that after its infusion, each of the six vials would receive a certain concentration of dye. Therefore, using an absorbance measurement device (SpectraMax), the absorbance value is linkable to an amount of dye. With this system, the lower the standard deviation between vials, the better or more uniform the mixing of the drug in the blood upstream of the arterial branch.

Two fluids (water and the blood substitute) containing the same concentration of dye were chosen as the model drug fluid to understand the influence of viscosity on mixing. The data verified that solutions with viscosity more alike the main fluid stream would exhibit better mixing. In this case, the model drug fluid, which was the blood substitute+dye, mixed more completely than when the model drug fluid was water+dye. Table 1 and Table 2, below, show the data.

TABLE 1 Ves- Ves- Ves- Ves- Ves- sel 1 sel 2 sel 3 sel 4 sel 5 Vessel 6 Water and Run 1 0.539 0.656 0.727 0.691 0.781 1.145 Dye Solution Run 2 0.519 0.639 0.692 0.652 0.777 1.181 Absorbance Run 3 0.505 0.632 0.710 0.623 0.748 1.138 Average 0.521 0.642 0.710 0.655 0.769 1.154 Infusion rate is 1.5 ml at 5 ml/min Average St. Dev. % RSD 0.742 0.218 29.4%

TABLE 2 Glycerol and 0.585 0.730 0.841 0.863 0.782 0.825 Dye Solution 0.604 0.727 0.826 0.868 0.778 0.819 Absorbance 0.618 0.713 0.808 0.856 0.787 0.821 Average 0.603 0.723 0.825 0.862 0.782 0.821 Infusion rate is 1.5 ml at 5 ml/min Avg. St. Dev. % RSD 0.769 0.094 12.3%

In Table 1 and Table 2, above, the data points are the absorbance values from each of the six branches. The % RSD values are the most important values to note. The experiments with the lower % RSD exhibited more uniform mixing. Therefore, as the data shows, the glycerol and dye solution (which is actually glycerol+water+dye) has a lower % RSD than the water and dye solution.

In summary, the uniformity or level of mixing can be seriously influenced by the viscosity of the model drug fluid and the difference between that viscosity and the viscosity of the main fluid stream (usually blood). The more similar the viscosities of the model drug fluid and the main fluid stream, the better the mixing. Therefore, one can tune the level of mixing desired by adjusting the viscosity of the deliverable.

Example 2

This set of experiments varies the distance from the delivery port of the catheter to the first branch point in the multi-branched vessels. The data is set out in Table 3, Table 4, and Table 5.

Each set of experiments uses a Veripath catheter. The model renal flow rate is 10 mL per second.

Table 3 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a proximal position—15 mm downstream of the aorta-renal-artery branch.

Table 4 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a middle position—40 mm downstream of the aorta-renal-artery branch.

Table 5 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a distal position—60 mm down-stream of the aorta-renal-artery branch.

FIG. 15 displays the standard deviations from Table 3, Table 4, and Table 5 for all three infusion rates and three delivery locations. As stated previously, this data supports the claims that for simple, single lumen catheter designs (Veripath), increased distance before bifurcations allows for better mixing. As ones moves closer to the bifurcations, mixing is increasingly difficult but lower injection rates can improve it.

TABLE 3 Infusion Rate Infusion Absorbance (mL/Min) Vol (mL) 1 2 3 4 5 6 1.0 0.2 0.1821 0.1607 0.1604 0.1601 0.1592 0.16 0.1618 0.1693 0.1657 0.1656 0.1684 0.1702 0.1723 0.17 0.165 0.1644 0.1669 0.17 Average 0.1721 0.1667 0.1637 0.1634 0.1648 0.1667 Stdev 0.010 0.005 0.003 0.003 0.005 0.006 Average 0.1662 COV 0.01923 Stdev 0.003196 5.0 1.0 0.5315 0.4689 0.4545 0.4326 0.456 0.462 0.4767 0.4738 0.4655 0.4774 0.4616 0.466 0.4774 0.4757 0.4615 0.4562 0.4618 0.4655 Average 0.4952 0.4728 0.4605 0.4554 0.4598 0.4645 Stdev 0.031 0.004 0.006 0.022 0.003 0.002 Average 0.4680 COV 0.03107 Stdev 0.014542 15 1.0 0.6828 0.6158 0.6181 0.6291 0.6297 0.6851 0.6213 0.629 0.6313 0.6287 0.6411 0.6866 0.611 0.619 0.6315 0.6227 0.635 0.6933 Average 0.6384 0.6213 0.6270 0.6268 0.6353 0.6883 Stdev 0.039 0.007 0.008 0.004 0.006 0.004 Average 0.6395 COV 0.03864 Stdev 0.024714

TABLE 4 Infusion Rate Infusion Absorbance (mL/Min) Vol (mL) 1 2 3 4 5 6 1.0 0.2 0.2018 0.182 0.1486 0.1659 0.1698 0.1604 0.1879 0.1835 0.1584 0.1641 0.1698 0.1615 0.1852 0.1809 0.1584 0.1695 0.1662 0.1619 Average 0.1916 0.1821 0.1551 0.1665 0.1686 0.1613 Stdev 0.009 0.001 0.006 0.003 0.002 0.001 Ave 0.1709 COV 0.07946 Stdev 0.01358 5.0 1.0 0.7179 0.6619 0.696 0.706 0.7029 0.8401 0.7509 0.7018 0.6852 0.6962 0.6973 0.8145 0.7637 0.6759 0.671 0.7062 0.7032 0.8071 Average 0.7442 0.6799 0.6841 0.7028 0.7011 0.8206 Stdev 0.024 0.020 0.013 0.006 0.003 0.017 Ave 0.7221 COV 0.07387 Stdev 0.053338 15 1.0 0.6306 0.5238 0.4875 0.4708 0.4626 0.5298 0.6399 0.5278 0.497 0.4814 0.5057 0.5285 0.6324 0.547 0.5078 0.5009 0.4968 0.5315 Average 0.6343 0.5329 0.4974 0.4844 0.4884 0.5299 Stdev 0.005 0.012 0.010 0.015 0.023 0.002 Ave 0.5279 COV 0.10627 Stdev 0.0561

TABLE 5 Infusion Rate Infusion Absorbance (mL/min) Vol (mL) 1 2 3 4 5 6 1.0 0.2 0.2739 0.1918 0.1928 0.1378 0.1291 0.1098 0.2723 0.1909 0.1921 0.1346 0.1275 0.1091 0.2767 0.191 0.1915 0.1332 0.1278 0.1096 Average 0.2743 0.1912 0.1921 0.1352 0.1281 0.1095 Stdev 0.002 0.000 0.001 0.002 0.001 0.000 Average 0.1718 COV 0.35334 Stdev 0.060704 5.0 1.0 1.3997 0.4679 0.5333 0.2654 0.2274 0.1467 1.4012 0.4615 0.522 0.2522 0.2284 0.1568 1.3916 0.4545 0.521 0.2451 0.2211 0.1456 Average 1.3975 0.4613 0.5254 0.2542 0.2256 0.1497 Stdev 0.005 0.007 0.007 0.010 0.004 0.006 Average 0.5023 COV 0.91925 Stdev 0.461737 15 1.0 2.2887 0.7998 0.4672 0.3156 0.3053 0.3499 2.3906 0.8032 0.4609 0.3144 0.3043 0.3466 2.2784 0.7921 0.462 0.3126 0.3008 0.3468 Average 2.3192 0.7984 0.4634 0.3142 0.3035 0.3478 Stdev 0.062 0.006 0.003 0.002 0.002 0.002 Average 0.7577 COV 1.03882 Stdev 0.787113

Example 3

This set of experiments varies the distance from the delivery port of the catheter to the first branch point in the multi-branched vessels. The data is shown in Table 6, Table 7, and Table 8.

Each set of experiments uses a VSH catheter. The model renal flow rate is 10 mL per second.

Table 6 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a proximal position—15 mm downstream of the aorta-renal-artery branch.

Table 7 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a middle position—40 mm downstream of the aorta-renal-artery branch.

Table 8 shows the absorbance data for a variety of model infusion rates and model drug volumes with the delivery port located at a distal position—60 mm down-stream of the aorta-renal-artery branch.

TABLE 6 Infusion Rate Infusion Absorbance (mL/min) Vol (mL) 1 2 3 4 5 6 1   0.2 0.1629 0.1597 0.1591 0.1588 0.1558 0.1602 0.1592 0.1593 0.1579 0.1576 0.1625 0.1622 0.161 0.1645 0.1697 0.1689 0.1678 0.1676 Average 0.1610 0.1612 0.1622 0.1618 0.1620 0.1633 Stdev 0.002 0.003 0.006 0.006 0.006 0.004 Ave 0.1619 COV 0.00516 Stdev 0.000835 5 1 0.4937 0.4959 0.4923 0.49 0.4886 0.494 0.5085 0.4959 0.4926 0.4932 0.4925 0.4939 0.51 0.5061 0.4943 0.4957 0.4844 0.492 Average 0.5041 0.4993 0.4931 0.4930 0.4885 0.4933 Stdev 0.009 0.006 0.001 0.003 0.004 0.001 Ave 0.4952 COV 0.01119 Stdev 0.00554 15 1 0.7234 0.7104 0.7177 0.7188 0.7133 0.7274 0.7139 0.7146 0.7238 0.7129 0.7174 0.7135 0.7073 0.7089 0.7113 0.7085 0.7165 0.7232 Average 0.7149 0.7113 0.7176 0.7134 0.7157 0.7214 Stdev 0.008 0.003 0.006 0.005 0.002 0.007 Ave 0.7157 COV 0.00488 Stdev 0.003495

TABLE 7 Infusion Rate Infusion Absorbance (mL/min) Vol (mL) 1 2 3 4 5 6 1   0.2 0.225 0.2063 0.2107 0.1777 0.1676 0.1672 0.1822 0.1872 0.1856 0.1824 0.1758 0.1693 0.1826 0.1795 0.1779 0.1709 0.1681 0.1676 Average 0.1966 0.1910 0.1914 0.1770 0.1705 0.1680 Stdev 0.025 0.014 0.017 0.006 0.005 0.001 Average 0.1824 COV 0.06641 Stdev 0.012114 5 1 0.5316 0.4874 0.4835 0.4611 0.4737 0.4839 0.4962 0.4846 0.4863 0.4831 0.4727 0.4753 0.4961 0.4857 0.4804 0.4753 0.4768 0.477 Average 0.5080 0.4859 0.4834 0.4732 0.4744 0.4787 Stdev 0.020 0.001 0.003 0.011 0.002 0.005 Average 0.4839 COV 0.02639 Stdev 0.012772 15 1 0.7906 0.7414 0.7416 0.7536 0.7344 0.7422 0.7505 0.7247 0.6959 0.7151 0.7118 0.7239 0.7381 0.6975 0.7035 0.7206 0.6962 0.7096 Average 0.7597 0.7212 0.7137 0.7298 0.7141 0.7252 Stdev 0.027 0.022 0.024 0.021 0.019 0.016 Average 0.7273 COV 0.02348 Stdev 0.01708

TABLE 8 Infusion Rate Infusion Absorbance (mL/min) Vol (mL) 1 2 3 4 5 6 1   0.2 0.1345 0.1906 0.1985 0.1806 0.1754 0.1486 0.1296 0.176 0.1892 0.1722 0.1686 0.1462 0.128 0.1787 0.1899 0.1689 0.167 0.1466 Average 0.1307 0.1818 0.1925 0.1739 0.1703 0.1471 Stdev 0.003 0.008 0.005 0.006 0.004 0.001 Average 0.1661 COV 0.13823 Stdev 0.02296 5 1 0.3901 0.6497 0.7698 0.5992 0.5672 0.3699 0.3751 0.6409 0.7499 0.6007 0.5663 0.3715 0.3867 0.633 0.7667 0.6166 0.5717 0.3675 Average 0.3840 0.6412 0.7621 0.6055 0.5684 0.3696 Stdev 0.008 0.008 0.011 0.010 0.003 0.002 Average 0.5551 COV 0.27519 Stdev 0.15276 15 1 0.5215 0.7946 0.9082 0.7524 0.6557 0.4282 0.5231 0.7502 0.8918 0.7608 0.6741 0.4198 0.4857 0.7351 0.8893 0.7467 0.6666 0.4313 Average 0.5101 0.7600 0.8964 0.7533 0.6655 0.4264 Stdev 0.021 0.031 0.010 0.007 0.009 0.006 Average 0.6686 COV 0.26009 Stdev 0.1739

Example 4

This set of experiments uses water as the carrier or system fluid. The model drug solution (red dye) is injected at a rate of 1 or 5 mL/min through a delivery catheter that is either a SCLS or SCE. The output of the catheter is located at a middle position (Mid) that is 40 mm downstream of the aorta-renal-artery branch or at a distal position (Distal) that is 60 mm downstream of the aorta-renal-artery branch.

The model kidney vasculature is the tortuous form. Table 9 sets out the data from this example.

Example 5

This set of experiments uses water as the carrier or system fluid. The model drug solution (red dye) is injected at a rate of 1 or 5 mL/min through a delivery catheter that is either a SCLS or SCE. The output of the catheter is located at a middle position (Mid) that is 40 mm downstream of the aorta-renal-artery branch or at a distal position (Distal) that is 60 mm downstream of the aorta-renal-artery branch.

The model kidney vasculature is the straight form.

The data in Table 9 shows the standard deviation of the absorbances for the various delivery positions.

Example 6

The kidney model uses a carrier fluid that models the fluid characteristics of blood.

This set of experiments uses a 36% glycerol in water solution as the carrier or system fluid. The model drug solution (red dye) is injected at a rate of 1 or 5 mL/min through a delivery catheter that is either a VSH or SCE. The output of the catheter is located at a middle position (Mid) that is 40 mm downstream of the aorta-renal-artery branch or at a distal position (Distal) that is 60 mm down-stream of the aorta-renal-artery branch.

The model kidney vasculature is the tortuous form.

The data in Table 9 shows the standard deviation of the absorbances for the various delivery positions.

Example 7

The kidney model uses a carrier fluid that models the fluid characteristics of blood.

This set of experiments uses a 36% glycerol in water solution as the carrier or system fluid. The model drug solution (red dye) is injected at a rate of 1 or 5 mL/min through a delivery catheter that is either a VSH or SCE. The output of the catheter is located at a middle position (Mid) that is 40 mm downstream of the aorta-renal-artery branch or at a distal position (Distal) that is 60 mm down-stream of the aorta-renal-artery branch. The model kidney vasculature is the straight form.

The data in Table 9 shows the standard deviation of the absorbances for the various delivery positions. Lower standard deviations in absorbance indicate more uniform absorbances vessel branch to vessel branch. From the data, drug uniformity depends on infusion rates, distances between the injection position and the vessel branch points, carrier fluid viscosity, and catheter shape.

Table 9 further supports that adding multiple deliver ports at the distal end of the catheter increases mixing. VSH is the same catheter as V but modified with side holes on the distal end. Once again, a lower COV indicates less variance between the six independent vessels better overall mixing. The data also shows that this improved mixing is most critical when the distance between the delivery site and vessel branching is small. Thus, it is critical to improve delivery catheters such that they are independent of location or infusion rate.

TABLE 9 Tortuous Anatomy Straight Anatomy 1 mL/min 5 mL/min 1 mL/min 5 mL/min Mid Distal Mid Distal Mid Distal Mid Distal System Fluid = Water SCLS 0.013972 0.047875 0.06308 0.243688 0.011099 0.027095 0.014617 0.065181 SCE 0.015054 0.010326 0.061896 0.044245 0.020484 0.042636 0.061705 0.191944 System Fluid = Glycerol Solution VSH 0.16224 0.086785 0.574318 0.465285 0.017992 0.018809 0.051321 0.096049 SCE 0.131551 0.19444 1.021261 1.014982 0.019935 0.060396 0.045216 0.258866

TABLE 10 Catheter Type Delivery Location 1 mL/Min 5 mL/Min 15 mL/Min V Proximal 0.01923 0.03107 0.03864 VSH Proximal 0.00516 0.01119 0.00488 V Middle 0.07946 0.07387 0.10627 VSH Middle 0.06641 0.02639 0.02348 V Distal 0.35334 0.91925 1.03882 VSH Distal 0.13823 0.27519 0.26009

The experiments that go along with Example 8, Example 9, and Example 10 vary the catheter type, the infusion rates, the infusion volumes of model drug solutions, and the anatomy model. The data for these examples is set out in Table 11.

Example 8

This set of experiment uses a tortuous anatomy as the kidney vasculature model and water as the carrier fluid. It uses an SCE delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between a and 5 mL per minute.

Example 9

This set of experiment uses a tortuous anatomy as the kidney vasculature model and water as the carrier fluid. It uses an SCLS delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between a and 5 mL per minute.

Example 10

This set of experiment uses a tortuous anatomy as the kidney vasculature model and water as the carrier fluid. It uses an VSH delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between a and 5 mL per minute.

TABLE 11 SCE vs. SCLS vs. VSH Rate Vol (mL) 1 2 3 4 5 6 SCE Mid 1 0.2 0.1422 0.1704 0.1764 0.1779 0.1813 0.1559 0.1444 0.1717 0.1811 0.1792 0.1778 0.1561 0.1444 0.1788 0.1796 0.1864 0.1751 0.1596 Average 0.1437 0.1736 0.1790 0.1812 0.1781 0.1572 Stdev 0.001 0.005 0.002 0.005 0.003 0.002 Average 0.1688 Stdev 0.015054 5 1   0.417 0.5382 0.561 0.5539 0.5569 0.4653 0.4088 0.5426 0.5667 0.5568 0.5465 0.4695 0.4092 0.545 0.5688 0.5564 0.5472 0.4661 Average 0.4117 0.5419 0.5655 0.5557 0.5502 0.4670 Stdev 0.005 0.003 0.004 0.002 0.006 0.002 Average 0.5153 Stdev 0.061896 Distal 1 0.2 0.0907 0.0897 0.1044 0.099 0.1135 0.1115 0.093 0.0904 0.1066 0.1005 0.1157 0.113 0.0917 0.0908 0.1063 0.1009 0.1154 0.1131 Average 0.0918 0.0903 0.1058 0.1001 0.1149 0.1125 Stdev 0.001 0.001 0.001 0.001 0.001 0.001 Average 0.1026 Stdev 0.010326 5 1   0.4977 0.3991 0.4679 0.4093 0.5009 0.4821 0.5018 0.4015 0.4721 0.4114 0.4993 0.4833 0.5031 0.401 0.4663 0.414 0.5024 0.4812 Average 0.5009 0.4005 0.4688 0.4116 0.5009 0.4822 Stdev 0.003 0.001 0.003 0.002 0.002 0.001 Average 0.4608 Stdev 0.044245 SCLS Mid 1 0.2 0.1705 0.1952 0.1994 0.1978 0.2058 0.177 0.1721 0.1969 0.2034 0.2003 0.2034 0.1778 0.1713 0.1968 0.2036 0.2083 0.2006 0.1791 Average 0.1713 0.1963 0.2021 0.2021 0.2033 0.1780 Stdev 0.001 0.001 0.002 0.005 0.003 0.001 Average 0.1922 Stdev 0.013972 5 1   0.6582 0.715 0.7166 0.6516 0.6645 0.5495 0.6261 0.7226 0.7125 0.6578 0.6499 0.5511 0.6179 0.7256 0.716 0.6543 0.6564 0.5429 Average 0.6341 0.7211 0.7150 0.6546 0.6569 0.5478 Stdev 0.021 0.005 0.002 0.003 0.007 0.004 Average 0.6549 Stdev 0.06308 Distal 1 0.2 0.1094 0.1518 0.1724 0.1889 0.2197 0.2432 0.1106 0.1526 0.1759 0.191 0.2175 0.2446 0.1096 0.1532 0.1753 0.1987 0.2145 0.2473 Average 0.1099 0.1525 0.1745 0.1929 0.2172 0.2450 Stdev 0.001 0.001 0.002 0.005 0.003 0.002 Average 0.1820 Stdev 0.047875 5 1   0.3851 0.3831 0.5016 0.6061 0.7492 1.006 0.3522 0.3877 0.4981 0.604 0.738 1.0085 0.344 0.3904 0.4959 0.6059 0.724 1.0044 Average 0.3604 0.3871 0.4985 0.6053 0.7371 1.0063 Stdev 0.022 0.004 0.003 0.001 0.013 0.002 Average 0.5991 Stdev 0.243688 VSH Mid 1 0.2 0.225 0.2063 0.2107 0.1777 0.1676 0.1672 0.1822 0.1872 0.1856 0.1824 0.1758 0.1693 0.1826 0.1795 0.1779 0.1709 0.1681 0.1676 Average 0.1966 0.1910 0.1914 0.1770 0.1705 0.1680 Stdev 0.025 0.014 0.017 0.006 0.005 0.001 Average 0.1824 Stdev 0.012114 5 1   0.5316 0.4874 0.4835 0.4611 0.4737 0.4839 0.4962 0.4846 0.4863 0.4831 0.4727 0.4753 0.4961 0.4857 0.4804 0.4753 0.4768 0.477 Average 0.5080 0.4859 0.4834 0.4732 0.4744 0.4787 Stdev 0.020 0.001 0.003 0.011 0.002 0.005 Average 0.4839 Stdev 0.012772 Distal 1 0.2 0.1345 0.1906 0.1985 0.1806 0.1754 0.1486 0.1296 0.176 0.1892 0.1722 0.1686 0.1462 0.128 0.1787 0.1899 0.1689 0.167 0.1466 Average 0.1307 0.1818 0.1925 0.1739 0.1703 0.1471 Stdev 0.003 0.008 0.005 0.006 0.004 0.001 Average 0.1661 Stdev 0.02296 5 1   0.3901 0.6497 0.7698 0.5992 0.5672 0.3699 0.3751 0.6409 0.7499 0.6007 0.5663 0.3715 0.3867 0.633 0.7667 0.6166 0.5717 0.3675 Average 0.3840 0.6412 0.7621 0.6055 0.5684 0.3696 Stdev 0.008 0.008 0.011 0.010 0.003 0.002 Average 0.5551 Stdev 0.15276

The experiments that go along with Example 11 and Example 12 vary the catheter type, the infusion rates, infusion volumes of model drug solutions, the catheter type, and the anatomy model. The data for these examples is set out in Table 12.

Example 11

This set of experiment uses a tortuous anatomy as the kidney vasculature model and a 36% glycerol in water solution as the carrier fluid. It uses an SCE delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between 1 and 5 mL per minute.

Example 12

This set of experiment uses a tortuous anatomy as the kidney vasculature model and a 36% glycerol in water as the carrier fluid. It uses an SCLS delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between a and 5 mL per minute.

TABLE 12 VSH v. SCE Rate Vol (mL) 1 2 3 4 5 6 VSH Mid 1 0.2 0.4427 0.3755 0.0618 0.1477 0.2185 0.0609 0.4442 0.3874 0.0636 0.1465 0.2237 0.0618 0.4414 0.389 0.0632 0.1466 0.2183 0.0623 Average 0.4428 0.3840 0.0629 0.1469 0.2202 0.0617 Stdev 0.001 0.007 0.001 0.001 0.003 0.001 Average 0.2197 Stdev 0.16224 5 1   1.4497 2.0984 0.5799 0.934 0.6098 0.8345 1.5643 1.9771 0.5881 0.9453 0.6088 0.8257 Average 1.5070 2.0378 0.5840 0.9397 0.6093 0.8301 Stdev 0.081 0.086 0.006 0.008 0.001 0.006 Average 1.0846 Stdev 0.574318 Distal 1 0.2 0.1721 0.2135 0.2553 0.231 0.4189 0.1832 0.1722 0.2228 0.2502 0.2298 0.4135 0.186 0.1721 0.2212 0.2515 0.2379 0.403 0.1843 Average 0.1721 0.2192 0.2523 0.2329 0.4118 0.1845 Stdev 0.000 0.005 0.003 0.004 0.008 0.001 Average 0.2455 Stdev 0.086785 5 1   0.7909 0.5286 1.7092 1.2844 0.8921 0.5451 0.788 0.5224 1.6681 1.4286 0.8791 0.5477 Average 0.7895 0.5255 1.6887 1.3565 0.8856 0.5464 Stdev 0.002 0.004 0.029 0.102 0.009 0.002 Average 0.9654 Stdev 0.465285 SCE Mid 1 0.2 0.034 0.0608 0.3438 0.306 0.2744 0.2466 0.0342 0.0602 0.3506 0.305 0.2723 0.2474 0.0336 0.0598 0.3491 0.2977 0.2757 0.2472 Average 0.0339 0.0603 0.3478 0.3029 0.2741 0.2471 Stdev 0.000 0.001 0.004 0.005 0.002 0.000 Average 0.2110 Stdev 0.131551 5 1   0.0347 0.173 2.5453 0.8329 1.7823 0.2136 0.0345 0.1743 2.5265 0.8259 1.7946 0.211 Average 0.0346 0.1737 2.5359 0.8294 1.7885 0.2123 Stdev 0.000 0.001 0.013 0.005 0.009 0.002 Average 0.9291 Stdev 1.021261 Distal 1 0.2 0.0345 0.3724 0.5609 0.1836 0.09 0.204 0.0389 0.3841 0.5605 0.1841 0.0907 0.2088 0.0415 0.3848 0.5554 0.1855 0.0892 0.197 Average 0.0383 0.3804 0.5589 0.1844 0.0900 0.2033 Stdev 0.004 0.007 0.003 0.001 0.001 0.006 Average 0.2426 Stdev 0.19444 5 1   0.0364 2.208 2.126 0.3518 0.0959 0.2766 0.0364 2.2826 1.9397 0.3606 0.0992 0.2683 Average 0.0364 2.2453 2.0329 0.3562 0.0976 0.2725 Stdev 0.000 0.053 0.132 0.006 0.002 0.006 Average 0.8401 Stdev 1.014982

The experiments that go along with Example 13 and Example 14 vary the catheter type, the infusion rates, infusion volumes of the model drug solutions, the catheter type, and the anatomy model. The data for these examples is set out in Table 13.

Example 13

This set of experiment uses a straight anatomy as the kidney vasculature model and a 36% glycerol in water solution as the carrier fluid. It uses an VSH delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between 1 and 5 mL per minute.

Example 14

This set of experiment uses a tortuous anatomy as the kidney vasculature model and a 36% glycerol in water as the carrier fluid. It uses an SCE delivery catheter.

The data shows the effect of varying the injection point between mid and distal positions, as described above.

The data shows the effect of varying the infusion volume of the model drug solution between 0.2 and 1 mL and of varying the infusion rate between a and 5 mL per minute.

TABLE 13 Straight Anatomy with Bood Substitute (36% Glycerol, 3.5 cp) Rate Vol (mL) 1 2 3 4 5 6 VSH Mid 1 0.2 0.1905 0.1858 0.1634 0.1756 0.2041 0.2112 0.1911 0.1838 0.1629 0.1795 0.2094 0.2162 0.1917 0.1848 0.163 0.1835 0.2023 0.2114 Average 0.1911 0.1848 0.1631 0.1795 0.2053 0.2129 Stdev 0.001 0.001 0.000 0.004 0.004 0.003 Average 0.1895 Stdev 0.017992 5 1   0.5299 0.5427 0.6028 0.5861 0.5473 0.4512 0.5221 0.5433 0.6045 0.5728 0.5355 0.4509 0.5219 0.5458 0.6033 0.5755 0.5396 0.4593 Average 0.5246 0.5439 0.6035 0.5781 0.5408 0.4538 Stdev 0.005 0.002 0.001 0.007 0.006 0.005 Average 0.5408 Stdev 0.051321 Distal 1 0.2 0.2598 0.2305 0.1978 0.2081 0.2168 0.2144 0.2481 0.2337 0.1994 0.2078 0.2146 0.2133 0.2473 0.2315 0.201 0.2075 0.2253 0.2117 Average 0.2517 0.2319 0.1994 0.2078 0.2189 0.2131 Stdev 0.007 0.002 0.002 0.000 0.006 0.001 Average 0.2205 Stdev 0.018809 5 1   0.6609 0.5983 0.5358 0.5848 0.764 0.7963 0.6706 0.6037 0.5331 0.5907 0.7546 0.7689 0.652 0.5937 0.5321 0.6194 0.7379 0.7737 Average 0.6612 0.5986 0.5337 0.5983 0.7522 0.7796 Stdev 0.009 0.005 0.002 0.019 0.013 0.015 Average 0.6539 Stdev 0.096049 SCE Mid 1 0.2 0.1779 0.1801 0.2359 0.2247 0.2132 0.2104 0.1764 0.1818 0.215 0.2195 0.2143 0.2095 0.1768 0.1817 0.2137 0.2194 0.2152 0.2091 Average 0.1770 0.1812 0.2215 0.2212 0.2142 0.2097 Stdev 0.001 0.001 0.012 0.003 0.001 0.001 Average 0.2041 Stdev 0.019935 5 1   0.4833 0.4892 0.568 0.5877 0.5676 0.5393 0.4838 0.4851 0.5835 0.5863 0.5709 0.5422 0.4799 0.4839 0.5661 0.5816 0.571 0.5357 Average 0.4823 0.4861 0.5725 0.5852 0.5698 0.5391 Stdev 0.002 0.003 0.010 0.003 0.002 0.003 Average 0.5392 Stdev 0.045216 Distal 1 0.2 0.1688 0.1535 0.1675 0.1835 0.2663 0.2952 0.1689 0.1569 0.1684 0.1822 0.2579 0.2941 0.1664 0.1532 0.1684 0.1809 0.2588 0.3152 Average 0.1680 0.1545 0.1681 0.1822 0.2610 0.3015 Stdev 0.001 0.002 0.001 0.001 0.005 0.012 Average 0.2059 Stdev 0.060396 5 1   0.4521 0.3895 0.4705 0.529 0.8824 1.0209 0.4451 0.3944 0.4669 0.5275 0.8672 1.0232 0.4424 0.3965 0.4669 0.5247 0.8822 0.9999 Average 0.4465 0.3935 0.4681 0.5271 0.8773 1.0147 Stdev 0.005 0.004 0.002 0.002 0.009 0.013 Average 0.6212 Stdev 0.258866 SCLS Mid 1 0.2 0.2084 0.1764 0.2065 0.2435 0.1619 0.1782 0.1862 0.1683 0.2107 0.1927 0.1594 0.2112 0.185 0.167 0.2108 0.1931 0.1593 0.1826 Average 0.1932 0.1706 0.2093 0.2098 0.1602 0.1907 Stdev 0.013 0.005 0.002 0.029 0.001 0.018 Average 0.1890 Stdev 0.020171 5 1   0.5035 0.4494 0.6234 0.5702 0.4912 0.5933 0.5381 0.4396 0.6265 0.5606 0.5168 0.5584 0.4965 0.4422 0.6214 0.5459 0.496 0.5975 Average 0.5127 0.4437 0.6238 0.5589 0.5013 0.5831 Stdev 0.022 0.005 0.003 0.012 0.014 0.021 Average 0.5373 Stdev 0.064329 Distal 1 0.2 0.3004 0.2355 0.1856 0.1618 0.1691 0.1489 0.259 0.2777 0.1902 0.1608 0.1633 0.1532 0.2801 0.248 0.1999 0.1739 0.1584 0.1503 Average 0.2798 0.2537 0.1919 0.1655 0.1636 0.1508 Stdev 0.021 0.022 0.007 0.007 0.005 0.002 Average 0.2009 Stdev 0.053399 5 1   0.8424 0.725 0.52 0.4029 0.5028 0.5683 0.819 0.7156 0.5294 0.3992 0.4966 0.5739 0.8196 0.7103 0.5243 0.3955 0.5164 0.5687 Average 0.8270 0.7170 0.5246 0.3992 0.5053 0.5703 Stdev 0.013 0.007 0.005 0.004 0.010 0.003 Average 0.5906 Stdev 0.155269

Example 15

For the data set out in Table 14, the absorbances for 3 experiments using each of the catheters listed below were measured for each of the six model kidney vessels. From these data, the mean, standard deviation, and coefficients of variance (COV) were calculated for each of the 3 experiments. Smaller COVs indicate more uniform absorbances within the six model kidney vessels. More uniform absorbances indicate better mixing of the model drug solution and model blood upstream of the point in the model kidney the six vessels branch from.

For the data labeled normal flow in Table 14, the experiments used a model blood pressure of 120/80, a model renal flow rate of 612 ml/min and a model heart rate of 62 beats per minute. This data is also depicted in FIG. 19.

The injection position was middle, as described above.

The rate that the model drug solution was infused was 5 ml per minute and the model drug solution volume was 1 ml.

For the data labeled slow flow in Table 14, the experiments used a model blood pressure of 100/60, a model renal flow rate of 432 ml/min and a model heart rate of 62 beats per minute. FIG. 19 depicts this data, as well.

The injection position was middle, as described above.

The rate that the model drug solution was infused was 5 ml per minute and the model drug solution volume was 1 ml.

TABLE 14 Device COV Normal Flow SC (1) 0.668639945 SC (2) 0.690450761 SC (3) 0.674122032 SCLS (1) 0.573040081 SCLS (2) 0.448106471 SCLS (3) 0.42978025 AN (1) 0.203495165 AN (2) 0.255781741 AN (3) 0.277323529 SB (1) 0.492903129 SB (2) 0.495742927 SB (3) 0.464743142 PSB (1) 0.222154851 PSB (2) 0.254763199 PSB (3) 0.254763199 BOIC2 (1) 0.251521383 BOIC2 (2) 0.261069332 BOIC2 (3) 0.263830656 BOIC4 (1) 0.047100437 BOIC4 (2) 0.044627776 BOIC4 (3) 0.031104892 Slow Flow SC (1) 0.701573548 SC (2) 0.675331237 SC (3) 0.684994408 SCLS (1) 0.431040508 SCLS (2) 0.434914758 SCLS (3) 0.295938149 AN (1) 0.400903854 AN (2) 0.41760533 AN (3) 0.357134811 SB (1) 0.479926197 SB (2) 0.502559424 SB (3) 0.459681637 PSB (1) 0.348541956 PSB (2) 0.333924232 PSB (3) 0.267846673 BOIC2 (1) 0.433731283 BOIC2 (2) 0.423053842 BOIC2 (3) 0.43001733 BOIC4 (1) 0.039802648 BOIC4 (2) 0.048597524 BOIC4 (3) 0.037685885

In this experiment, SC is a single lumen delivery device similar to the V catheter in previous examples. SCLS is the SC catheter with side holes in the distal end similar to the VSH catheter in previous examples. Data from Table 14 shows that an expandable diffusion member such as a balloon improves mixing more than a simple, single lumen delivery device or one with side holes improves mixing. Balloon expansion causes partial obstruction of the vessel resulting in turbulent flow around the balloon, which improves mixing. The degree of obstruction plays a role in the degree of mixing as the BOIC2 (inflated to 2 atm) is about 60% of the vessel ID versus the BOIC4 (inflated to 4 atm) is about 90% of the vessel ID.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications can be made without departing from the embodiments of this invention in its broader aspects and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true, intended, explained, disclose, and understood scope and spirit of this invention's multitudinous embodiments and alternative descriptions.

Additionally, various embodiments have been described above. For convenience's sake, combinations of aspects composing invention embodiments have been listed in such a way that one of ordinary skill in the art may read them exclusive of each other when they are not necessarily intended to be exclusive. But a recitation of an aspect for one embodiment is meant to disclose its use in all embodiments in which that aspect can be incorporated without undue experimentation. In like manner, a recitation of an aspect as composing part of an embodiment is a tacit recognition that a supplementary embodiment exists that specifically excludes that aspect. All patents, test procedures, and other documents cited in this specification are fully incorporated by reference to the extent that this material is consistent with this specification and for all jurisdictions in which such incorporation is permitted.

Moreover, some embodiments recite ranges. When this is done, it is meant to disclose the ranges as a range, and to disclose each and every point within the range, including end points. For those embodiments that disclose a specific value or condition for an aspect, supplementary embodiments exist that are otherwise identical, but that specifically exclude the value or the conditions for the aspect.

Finally, headings are for the convenience of the reader and do not alter the meaning or content of the disclosure or the scope of the claims. 

What is claimed is:
 1. A method comprising delivering a solution having a concentration of a therapeutic agent to an organ having branched vessels wherein delivering comprises at least one step that improves the therapeutic agent concentration uniformity among the branched vessels, wherein the step that improves the therapeutic agent concentration comprises normalizing a viscosity of the therapeutic agent solution towards that of blood such that a relative standard deviation measurement corresponding to the concentration uniformity of the therapeutic agent among the branched vessels is less than 29 percent.
 2. The method of claim 1 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels further comprises a step of delivering a delivery catheter comprising a delivery port such that the deployed position of the delivery catheter causes the delivery port to be located downstream enough of any upstream arterial branches not leading to the organ to prevent substantial drug delivery down the upstream arterial branches and upstream enough of the organ to allow substantial mixing of the solution with the blood; delivering a delivery catheter comprising a delivery port with a geometry that causes increased mixing between the blood and therapeutic agent solution; delivering a delivery catheter comprising at least one delivery port and at least one diffusion member wherein the diffusion member fosters increased turbulence near or downstream of the delivery port; decreasing the infusion rate of the therapeutic agent solution; or increasing the number of delivery ports.
 3. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of delivering a delivery catheter comprising a delivery port with a geometry that causes increased mixing between the blood and therapeutic agent solution.
 4. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of delivering a delivery catheter comprising at least one delivery port and at least one diffusion member wherein the diffusion member fosters increased turbulence near or downstream of the delivery port.
 5. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of decreasing the infusion rate of the therapeutic agent solution.
 6. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of increasing the number of delivery ports.
 7. The method of claim 2 wherein improving the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the average amount of drug delivered to each vessel falls within a range defined as a 85, 90, 95, 98, or 99 percent confidence interval calculated from a standard deviation of the average amount of drug delivered for the vessel with the highest such standard deviation.
 8. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the highest concentration falls within a maximum therapeutic dose while the total drug delivery to the vessel that receives the lowest concentration is 100-300 percent of a minimum therapeutic dose.
 9. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds a minimum therapeutic dose while the total drug delivery to the vessel that receives the highest concentration is 75-175 percent of a maximum therapeutic dose.
 10. The method of claim 2 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of delivering a delivery catheter comprising a delivery port such that the deployed position of the delivery catheter causes the delivery port to be located downstream enough of any upstream arterial branches not leading to the organ to prevent substantial drug delivery down the upstream arterial branches and upstream enough of the organ to allow substantial mixing of the solution with the blood.
 11. The method of claim 1 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds a minimum therapeutic dose while the total drug delivery to the vessel that receives the highest concentration is 50-200 percent of a maximum therapeutic dose.
 12. The method of claim 11 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds a minimum therapeutic dose while the total drug delivery to the vessel that receives the highest concentration is 75-175 percent of a maximum therapeutic dose.
 13. The method of claim 12 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds a minimum therapeutic dose while the total drug delivery to the vessel that receives the highest concentration is 90-150 percent of a maximum therapeutic dose.
 14. The method of claim 1 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the highest concentration falls within a maximum therapeutic dose while the total drug delivery to the vessel that receives the lowest concentration is 100-300 percent of a minimum therapeutic dose.
 15. The method of claim 14 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the highest concentration falls within a maximum therapeutic dose while the total drug delivery to the vessel that receives the lowest concentration is 150-250 percent of a minimum therapeutic dose.
 16. The method of claim 15 wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the highest concentration falls within a maximum therapeutic dose while the total drug delivery to the vessel that receives the lowest concentration is 175-225 percent of a minimum therapeutic dose.
 17. The method of claim 1 wherein improving the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the average amount of drug delivered to each vessel falls within a range defined as a 85, 90, 95, 98, or 99 percent confidence interval calculated from a standard deviation of the average amount of drug delivered for the vessel with the highest such standard deviation.
 18. A method comprising delivering a solution having a concentration of a therapeutic agent to an organ having branched vessels wherein delivering comprises at least one step that improves the therapeutic agent concentration uniformity among the branched vessels; wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of normalizing the viscosity of a therapeutic agent solution towards that of blood; delivering a delivery catheter comprising a delivery port such that the deployed position of the delivery catheter causes the delivery port to be located downstream enough of any upstream arterial branches not leading to the organ to prevent substantial drug delivery down the upstream arterial branches and upstream enough of the organ to allow substantial mixing of the solution with the blood; delivering a delivery catheter comprising a delivery port with a geometry that causes increased mixing between the blood and therapeutic agent solution; delivering a delivery catheter comprising at least one delivery port and at least one diffusion member wherein the diffusion member fosters increased turbulence near or down-stream of the delivery port; decreasing the infusion rate of the therapeutic agent solution; or increasing the number of delivery ports; and wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the highest concentration falls within a maximum therapeutic dose while the total drug delivery to the vessel that receives the lowest concentration is 100-300 percent of a minimum therapeutic dose.
 19. A method comprising delivering a solution having a concentration of a therapeutic agent to an organ having branched vessels wherein delivering comprises at least one step that improves the therapeutic agent concentration uniformity among the branched vessels; wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of normalizing the viscosity of the therapeutic agent solution towards that of blood; delivering a delivery catheter comprising a delivery port such that the deployed position of the delivery catheter causes the delivery port to be located downstream enough of any upstream arterial branches not leading to the organ to prevent substantial drug delivery down the upstream arterial branches and upstream enough of the organ to allow substantial mixing of the solution with the blood; delivering a delivery catheter comprising a delivery port with a geometry that causes increased mixing between the blood and therapeutic agent solution; delivering a delivery catheter comprising at least one delivery port and at least one diffusion member wherein the diffusion member fosters increased turbulence near or down-stream of the delivery port; decreasing the infusion rate of the therapeutic agent solution; or increasing the number of delivery ports; and wherein a step that improves the therapeutic agent concentration uniformity among the branched vessels means that the range of therapeutic agent concentrations delivered to the vessels is small enough so that the total drug delivery to the vessel that receives the lowest concentration exceeds a minimum therapeutic dose while the total drug delivery to the vessel that receives the highest concentration is 50-200 percent of a maximum therapeutic dose.
 20. A method comprising delivering a solution having a concentration of a therapeutic agent to an organ having branched vessels wherein delivering comprises at least one step that improves the therapeutic agent concentration uniformity among the branched vessels, wherein the step that improves the therapeutic agent concentration uniformity among the branched vessels comprises a step of delivering a delivery catheter comprising a delivery port and a self-expanding diffusion member such that a deployed position of the delivery catheter causes the delivery port to be located downstream enough of any upstream arterial branches not leading to the organ to prevent substantial drug delivery down the upstream arterial branches and upstream enough of the organ to allow substantial mixing of the solution with a turbulent blood flow caused by a flow of the blood through the self-expanding diffusion member prior to delivering the solution to the organ. 